1. Field of the Invention
The present invention relates, generally, to connectors for joining two structural components together and, more especially, to such a connector for joining water-borne components which may be subjected to bending, shear, tensional and/or torsional forces at the joint.
2. Description of the Background Art
Myriad devices have been proposed for joining structural components together. Where the structural components are buoyant and designed to be water-borne, many restrictions are imposed upon the design of a simple yet highly efficient connector device. As opposed to connections for components bottomed on a solid foundation, the fluid underpinning for a buoyant structure coupled with climatic variations complicates considerably the design of an effective connector while the environment demands high reliability in use.
U.S. Pat. No. 2,565,369 discloses a form of articulated floating platform where the components are joined by a type of hinge. The connector includes a shock absorbing member which, in combination with the hinge, is disclosed to permit twisting of one platform vis-a-vis its neighbor. Thus, the connector structure disclosed in this patent allows for some relative freedom of movement between adjacent platforms.
U.S. Pat. No. 2,798,448 discloses a coupler for use in joining barges together in a semi-rigid manner. The coupling includes a pair of base assemblies mounted for rotation on vertical axes on either of the barge members to be joined, a connecting block pivotally mounted on a horizontal axis, and a connecting bar extending between the assemblies. The coupling permits some vertical movement of the barges with respect to each other due to the pivotal mounting of the block with respect to the base. This is augmented somewhat by a spring which further serves as a type of shock absorber. Hence, some relative movement of the connected barges is permitted while coupling is maintained.
U.S. Pat. No. 3,091,203 discloses yet another approach for connecting buoyant members together to form a wharf. In general, the sections of the wharf are separated by a resilient pad through which passes a fastener such as a flexible metal cable designed to maintain a compressive force across the juncture. A metal rod may be used in lieu of the cable in this connector structure. This approach, when a metal rod is employed, will minimize the ability of one component to shift vis-a-vis another. Where a cable is used as a connector element between or array a number of units, it is expected that over there will be lateral separation at the joint between adjacent components over a period of time.
Another floating structure including a connector joint is disclosed in U.S. Pat. No. 3,276,209. This approach secures a pair of floating members by an "H"-shaped connector formed by joining two "T"-shaped metal elements along the single axis by a resilient polymeric pad. The arms of the overall "H" connector are secured to adjacent structural components by means of fixture bolts or the like. It is expected that the resiliency of the intermediate polymeric pad in this connector will permit some limited movement between the members. An alternate approach is also disclosed in this patent, that being a type of hinge including a shock absorber, the overall approach being fairly similar in conceptual terms to that disclosed in the aforementioned '369 patent.
U.S. Pat. No. 3,306,053 discloses a connector for use in joining concrete piers or pontoons to form a dock. In general, a heavy rubber pad is interposed between adjacent dock sections within opposing recesses formed therein. The rubber block is maintained in position by means of a stainless cable extending across the juncture. The cable is stressed to hold the adjacent dock sections together and maintain the positioning of the intermediate pad. This arrangement is disclosed to restrict motion between adjacent structures except in a buckling mode.
U.S. Pat. Nos. 3,645,225 and 3,799,100 disclose a flexible connector for, e.g., joining a tug and barge together. The connector is comprised of a number of resilient posts which fit within opposing bores or channels in the tug and barge to be joined. The post is specially configured to be received in locking engagement achieved through a circumferentially restricted intermediate portion near either end of the post and cooperating engagement bars associated with the tug/barge members which fit within the restriction and prevent the post from being withdrawn.
Certain of the foregoing connector designs permit or accommodate relative motion between the structures joined by the connector, whereas some seek to minimize this type of relative motion. In some instances, the connectors permit wide-ranging motion between adjacent components and do not appropriately restrict excessive or gross movement between the structures. Where one is concerned with the connection between water-borne structural components, it is necessary to accommodate a tendency for relative motion in quite a number of different directions while restricting gross motion between the components. Thus, for reliable and efficient connection, the connector itself should be able to tolerate bending, shear, tensional and/or torsional forces at the joint without failure while maintaining a positive interlock between adjacent structures. These forces, which have components in three independent directions (i.e., along mutually orthogonal xyz axes) result from wind and wave action as well as loading on the components themselves where the same are, e.g., pontoon members joined together to form a dock, wharf, breakwall or the like.
Thus, the need exists to provide an efficient connector for structural components, especially water-borne components such as pontoons or the like, which will restrain gross motion between adjacent components as the result of bending, shear, tensional and/or torsional forces existing or applied near or at the juncture.